No Smooth Operation
Thread Starter
Intermediate
Joined: Apr 2007
Posts: 43
Likes: 0
From: Virginia Beach VA
No Smooth Operation
I have finished the ZZ4/kiesler 5spd combo in my 72 convertible. I was having dificulty with the timing and carb tunning. I have since replaced the ZZ4 HEI distibuter with the Mallory unilit mech tach drive that was in my old motor. It does not have vac advance and I set timiing to 10 BTDC. The problem is every time I think I have things set the idle speed starts wondering and it seems to develop some rough spots in various rpm range. Looking for some help to figure this out. Thanks in advance.
Thread Starter
Intermediate
Joined: Apr 2007
Posts: 43
Likes: 0
From: Virginia Beach VA
This is the ZZ4 Turn key kit with serpintine belt system. The carb is a Holley 750, 4160 style vacume secondary, electric choke.GM part #12485506. In my initial attempts to tune the engine with the provided HEI ditributor The timing was wandering and I could not seem to get it set. I plugged every vacuum port on the carb and the idle is still bouncing. I have put my Mallory unilite mech tach drive distributor in and it has no vac advance. I have attempted to set the idle at 800rpm but it wants to bounce between 500 and 1100. This still sounds like a vacuum issue but I have plugged all ports and rechecked all carb and intake manifold bolts. I am stumped. Please HELP!
